Everytime I make a cake and try to remove it from the baking pan, the bottom tends to crumble. Sometimes the sides as well. I am greasing the pan but I was wondering if there are other techniques to prevent this.

A lot of cake recipes require that cake pans be floured as well as greased. The flour over the oil acts as a barrier between the batter and the pan. If you're baking a chocolate cake and don't want the white residue that's left behind to show up on your cake then you can use cocoa powder as a substitute for the flour.

A simple way to stop a cake from crumbling, is to place it for a few minutes in the refridgerator before trying to remove it from the baking pan. The freezing process allows the cake to become firm enough to remove without falling apart. Take care not to leave it in the cold for too long or face having a frozen cake. With proper timing the cake will be left warm and crumble free.

I always make my cake the day before I plan on icing it, and freeze it overnight. This cuts down the crumbles significantly. Then, always try a crumb coat, a thin layer of icing over the cake and under you main frosting. This works best with home mead icing that you can thin with water or milk, but you can also thin out some of the canned frosting as well in the same manner. With a crumb coat, you should not end up with chunky looking frosting on the top.